PERFORMANCE ANALYSIS OF TORQUE CONVERTER ELEMENTS

摘要

The hydraulic performance of a 3-element automotive torque converter is analyzed by making flow measurement with 5-hole Pitot tubes between these elements. The performance of each element, including head, head loss and efficiency, is defined and evaluated. The results show that the pump is the major source of loss in the speed ratio range where vehicles are most frequently operated in daily driving. The loss coefficients for the three elements are also evaluated using a 1-dimensional flow model. The friction loss coefficient of the turbine is nearly constant over the entire tested speed ratio range, whereas the coefficients of the pump and stator vary considerably according to the operating speed ratio. The cause of loss in the pump and stator is investigated by flow visualization and 3-dimensional numerical flow analysis. The procedure presented here is useful not only in improving performance prediction accuracy but also in determining a direction for design improvement.